Why is rune in golang an alias for int32 and not uint32?

Question

The type rune in Go is defined as

an alias for int32 and is equivalent to int32 in all ways. It is used, by conv

Answer 1

It doesn’t become negative. There are currently 1,114,112 codepoints in Unicode, which is far from 2,147,483,647 (0x7fffffff) – even considering all the reserved blocks.